Cement size



a AMERICAN, CEMENT. m M NY seems cases A s sl'asem 'oi;

' RGIA .1 in" 1 lcmmnr SIZE W in Drawing'." A inicamnmea March 22, 1929.Sex-1111110 349,277; A g 23 I i radii nvrienr nono'ss. as

t This invention relates, to a cement: sizing and a method of making thesame: 1; Almostfall stucco,'masonry and plaster surfaces contain freeIimeor other caustic materials:- This free alkali-often works slowlyoutward to the surface. When oil paints are applied to such surfaces,the alkali often causes saponification of the oil and consequentdisintegration of the paint'film. When water aints or calcimines areapplied to such sur aces, tlYe llme bften comes through to the surface,causing lime burns:

ands ottin .1 E'

The ordinary size preparations are -de-- signed solely to close up thepores in the sure: face and decrease suctiona Their use may decrease thetrouble from. free, alkali, but since they depend largely onmechanically locking in the alkali, and. are inthemselves. generallysomewhat porous, these ordinary size'preparations do not give thoroughsatis faction on suchsurfaces. f

Moreov er,wall surfaces are often mechan ically'weak or friable. ,Theordinary siz 111 tohg en the wall surface for perfect bonding of thefinish coat. Peeling of the paint film therefore often results. I .1 l

It is an object of the present invention to produce a cement sizingwhich maybe em ployed as a primmg coa and .is applicable to a number ofsurfaces, especially. stucco, concrete, masonry, plaster, and similarcem entitious wall surfaces. l

Another object of the invention is the provision of a-sizing which willsuccessfully; eliminate thetrouble from -free' alkalies" harden thesurfa m and form an inte ral 5y weig reparations do not alwayssufliciently' and destroy'or? the casems from milks. [1 1 In placeofthecaseins, a suitable quantity paints will not flake or peek- Thisinvention will be best would adhere and rom which surface such us tailed(description; nevertheless, it is to be? understood that the inventionis not confined to, the disclosure, being susceptible of such changesand modifications which shall del a5v fine no material departure fromthe salient in the} I Portland h binatipn, 0

ha a

scientifically "and properhoned amount of filler material, consistingchiefly of silica, preferably amor ho u verized limestone or marb e oror in con 1na i olifin proper quantity epen 1ng upon acttypeofPortlandorl natural hydraulic cement used. a

-{f A suitable quantity of sulfuric" casein"; muriatic casein, aceticcasein, or actic casein".

giggly or in cofibinatiomfiogether with at suita Iefqiiaititfif liin orborax' or other suitable solvent a ent. These caselns are of the commercal type and are namedin accord v ance with the acid-{employed toprecipitate;

of powdered soap with or without a suitable v i win- 1 I. I 1;, paints,proxylinlacquers and enamels,fl1n-- v dustrial flats, calc mines' orcement paints 4 p understood 6 from alconslderationof the following de if-'- Portland cement sue as that commercially raulic cement, sipgl p rnflcom-f a}; e amoun o from 0% to us white 7 silica plfiverizeduartz-or" s1 ex, c alk or p 1 other s li- 'ious or ca careous materialor matria s5 7 bond with the surface and produce a rm. gs hard and ieutralouter coating to which oil l-w. F l i i quantityof ri-sodium hoshate or other solvent a -ant-or a, gents, and Willi or without a a smallquant ty ofalum the soap to be chemi I 1,361,317 r ailiti ically inexcess if alum is used, may be emical or satisfactory except in very lare inployed. stallations handling large outputs. atch When desirable asuitable quantity of wamills, however, whether ball, pebble or tube,ter-soluble sodium silicate, or a suitable qua n are both economical andthoroughl satisfac- 1 yo acom ina 1on0 ecaseins soa and tory. Because ofthe different egrees of silicate may e su stitute or an sing einhardness of the different raw materials, the grement. A'suitablequantity of any other grinding can best be carried out in two ormaterial or materials, singly or in combinamore stages.

tion, which will insolution react with frge In makin a cement sizing,for example,

alkali to roduce an insoluble compound or commercial Tortland cement isloaded into a 75 compomch will physically absorb batch pebble m1 an reuce to a fineness of i or adsorb free alkali may be employed. aapproximately 85% through 300 mesh. This A small percentage of calciumcarbonate}, finely ground cement is then mixed with the 6 M togetherwith a proportionate quantity other in redients in the prop propo gimp,preferably a L um sulfateorasmall an is w o aded into a similar batchpercentage of ca cium sulfate or ground pebble mill and reduced to afineness'of apsul is mixed'i witft elia ove ingredignts. proximatejlfywlgfi gigmespl. Tllile sma l percentage 0 ta 0, soa stone 0 ma mixing, 0course, ta es p co in t e mi cla or asbestos si ngmr n ggm hmation, Thematerial is then dumped from. e with or without a suitable quantity ofpig packed in suitable contalners, and stored 85 ment matter completethe product. a I ready for shipment. a :1;

. or the most satisfactory results to be ob- To prepare this sizing ornndercoater for tained from the finished roduct, the allowuse it ismixed with water in the following able limits of variationo the degreeof, finemanner: The dr size is p aced in a mixing ness to which theinsoluble portions of the vessel, a proper amount of wat r added and 90size are ground-are rather small. If. these the whole stirred up untilthoroughly blended insoluble portions are too coarse, the cement into astiff paste. dditio er is then filmleft on the outer surface will be toorough slowly added,'with s irrlng, until t e mix-: for best results withsome of the finer finish ture is of the proper consistency for use. It

coatings. If these insoluble portions are too. is then applied to thewallsurface with a i fine, an unnecessarily large proportion of thebrush or spray gun. The exact proportion cement and other ingredientswill bedrawn of water to use for best results varies with dif into thepores of the surface. It has been ferent compositions of the sizing and,within found experimentally that a degree of finecertain-rather narrowlimits, with a sizin a5 ness whereby approximately 90% will Pam of anyone composition. 'The size as mixe 100 through athree hundred (300.)mesh sieve lies ready for use must be thin enou h so that 1''} within,these limits and gives thoroughly the soluble portions can enetrateeasily into satisfactory results.- The limits of variation the surfaceto lock in alhalinity and so that of fineness of the soluble portions isnot so the cement film left on the outer surface will 40 narrowly fixed.The greater the degree of not be. too thick, but thick enough so that a105 fineness the more rapidly solution takes lace. thin uniform coatingof cement will be left Since a cement size can most convemently on thesurface to overcoat. There are other he handled,packed-' and marketedintthe form factors, such as the tendency of the cement; of. ad Wder,the manufacturing process and other insoluble ingredients to settle out,y consfi hg s ehtmly of reducing the compo but the factors whichdetermine the limits of 11 nent raw materials to a suitable degree ,ofthe pro ortions of water" to powder are those fineness and thoroughlyblending them tostated a ve.- With a; size ofa certain corngether theproper proportions. position it has been found, for example, that r ofthe materials used can be commerbest results are obtained when themixture is so cially obtained-in powder or granularjorm. made up in theproportions of two quarts 1 They cannot, however, be economically obofter to two and one-half pounds of the tained in a degree of finenesssuitable for use n and that appreciable variations '-in a; size. Furtherreduction is therefore "e proportions, while possible, are

. necessary.

Any mill or grinding machine capable of --On surfaces of concrete,stucco, masonry, 12o

- reducing the materials to the'requisite degree laster and kindredsurfaces where free alof fineness might be used, whether of theimalies'are normally present in the surfaces,

pact or attrition type. Ball, pebble'or tube this size or undercoatereffectively locks up,

- mills are especially adaptable to the condiboth chemically andmechanically, such free tions met in manufacturing a eement'size.alkalies within the surface and prevents their 125 Continuous millsmight be used, but because working through to the outer surface, thereofthe large number of raw materials used to by insuring a neutral .outer'surface-I make up the size, and because of the differ By virtue of thecolloidal properties of a J 1 encesin the degrees of hardness. of thesemapart or all of the soluble materials used in terials continuousmillswould not be eoonomthis sizing, especially of the cement, ar 1d 1:0

comma "0a PLASTIC. 5}

virtueiof the hardening properties" of these colloidal materials, thisSiZlII toughensand for proper this cement film is terlacing crystalslocked together by the colloidal portions of the cement, and offering anexcellent surface to whichthe finish coat can tooth or bond.

Cement and J@ZerF-The cement reaction 18 e usua se m a d'hardemngreaction of hydraulic cement, that is: crystallization and the formationof a colloidal gel which hardens on setting, bindin together the crys-'tals; except that where ortland cement is used and where calcium sulfateis used or is present from the reaction of other materials,this'reaction is retarded or accelerated, depending on the relativeamount of calcium sulfate present. In a cement sizing it has been founddesirable to have calciumsulfate present in proper quantity toappreciably retard the setting action of the cement, as otherwise theSIZlII would have to be applied immediately after mixing. It has beenfound that by properly proportioning the calcium sulfate used, a sizemay be produced which may with thoroughly satisfactory re sults beapplied as much as four hours after mixing. The le 'al here used ischemically inert "toward the cement and serves simpl to give the mixturebody.

Uasez'nrulfuric casein, muriatic casein, acetic casein and lactic caseinare all in themselves but slightly solublein water. In the presence of asmall quantity of borax or lime or other alkali, however, all four arequite soluble and dissolve to gummy and viscous V colloidal substancesof pronounced adhesive of reacting properties. Portland cement normallycontains a small percentage of free lime. This lime would serve as asolvent for the casein if but a small amount of casein were used. a,

Borax and some other solvent agents, however, bring about the solutionof casein more rapidly than does lime and are therefore desirable' foruse in this connection. This colloidal caseinsolution possesses theproperty with lime or other free alkali to form a colloidalcasein-alkali com ound which hardens mto a Horny insoluble substance. Itis this reaction which makes casein valuable as an alkali-lockingmaterial. The casein solution also imparts certain other desirableproperties to the mixed sizing. It

cassette lowers'the' surface tension of the miiied ing and therebyimpartsdesirablemixing and spreading properties. Moreover, its ad-'hesive qualities help to hold the cementand other in redients to andwithin thewall sur''-. face until the cement has'set." Any one of thecas'eins may ly achi'eve'these results. It has been experi mentallyfound, however, that a mixture of sulfuric and lactic caseins, in theproper pro portions, gives a moreviscous solution than the samequantityof any one of the caseins sibnlglyg Such a; mixture is,therefore, desir a 1;. 80a .A soa usuall thesodium salt of stea r1c 6ralmi t' acid reac s w1 lmje o orm an nso u e line soap, calcium steer-,1ate or calcium a 'm'ltate. hereportland cement is use e ree limecontained in theceme'nt' of course reacts with the soap; An excess ofsoap must therefore be present to react with any free lime within thewall towhich the size is applied. When alum is used with thesoap, thesematerials react to form sodium sulfate and insoluble'aluminum' stearate"or aluminum palmitate. When al'fim'f' 1s used the soap mustt ere ore bein excess of that required'for reacting both'with the free limecontained in the cementand with the alum. These insoluble .aluminate orpalmitates serve to closeup the pores in the surface but they have atendency to come to the top of the mixed sizing and their use makes muchstirring of the mixed sizing n'ec 'essary. Neither soap alone nor soapand i f Ximiner be used 'singly to successful-L alum nor theirreaction'productshave the ad-' hesive properties of the casein solution.Either soap alone or soap and alum, therefore,.is somewhat inferior to'.casein for use in connection with a cement sizing. e 1 a =S0dz'umsilicat@.-Sodium silicate in solution reacts with lime to form'insoluble calcium silicate. The free limepresent in For an ceiriennecessitates a substantial quant-ity of silicate, and sodium. silicatein too great proportions is injurious to the proper hardening ofPortland cement so that whensodium silicate is employed a predeterminedquantity of a casein is used. i

- Zum and cal 'um a emanate-Alum in so u 1on reac s W]. ca c1umcarbonate to form calcium sulfate and aluminum hydroxide. The calciumsulfate seryes to retardor accelerate the setting action of the cement,if it 1s Portlan' d cement It has beenfou'nd desirable to use thesematerials in such quantity that the calcium sulfate formed will ap-'-preclably retard the setting of the cement.

This" retarding action. alone could be. ob-'- gypsum, which ischemically The aluminum hvdroxidek.

forms as a gelatinous preclpltaie orel,

however, which adds to the mixing and spreading properties of the sizingMore:

' over, this aluminum hydroxide hardens in the pores of the surface towhich the size is applied. It is therefore sometimes desirable to usealum and calcium carbonate instead of ground gypsum. Z

Talc, soagstone, china 0 asbestos and 2 meat matter. a c, soapstone,china clay,.ashestos and pigment matter are used for their physicalproperties only and are 5 chemically inen toward each otherandltoingredients are employed in the following proportionsn- 1: :5":yr- I" ;.i

. I N Per cent Portland cement 46.8 A p v p 10.6 25 Amorphous whitesilica ,'10.0 Chinac ay "5.9 Alum-.. j i a 4.7 c V p g 1. :0 Pigmentmatter f .8 za ieew 14?? 22'5. Lactic casein I '5.'5 Sulfuric casein..5.5 :Borax f ..1.8' ydrated 1ime J 3,5 Lili'i Total. .99.8 Where soap issubstituted for lactic casein 16 and sulfurlc casein approximately 11%of the soap may be employed for the purpose or with 5.5% soap.

caseinfurther aids in the production of a more adhesive substance in thefinal product articularly after the water has been addedl l i n such areaction alumippm hyd1p xide is formed which tends to blend with thecasein solution to add to the adhesiveness of the sizing and when theproduct is dry, after the application to a wall, the action ,of the 'hydroxide on the casein provides fora hard surface coating- F1 1 I Iclaim:i

11. A size comprising amixtureof as...

silica, china clay, talc, pigment-,

phous white a re-action product of Portland cement cal-j casein, borax,and hydrated lime.

' cium carbonate, alum, lactic casein, sulfuric fillers, Portlandcement, water, the reactionproducts of calcium carbonate, sulfuriccasein and lactic casein,

of sulfuric casein in used in connection- 1 2. A size comprisingamixture of mineraland alum including a regelatinous precipitate such asaluminum hydroxide which aids in the mixin of the size and which formsan insoluble er for the pores of the size when set. 3. A size comprisinga mixture of 10% amo h us silica, 6% china clay, 5% talc eigh en spercent of pigment matter, and a reaction product of 48% Portlandcement, 10% calcium carbonate, 4.7% arm-75.5% lactic casein, 5.5%sulfuric casein, 1.8% borax, and 3.5% hydrated lime. T

WILLIAM PAUL DWIGHT MOROSS. f

